Claude Opus 4.8 (Fast)

Fast-mode variant of [Opus 4.8](/anthropic/claude-opus-4.8) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode

5/27/2026

1,000,000 tokens

Specifications

Modalities

Input

text

image

file

Output

text

Supported Parameters

include_reasoning

max_tokens

reasoning

reasoning_effort

response_format

stop

structured_outputs

tool_choice

tools

verbosity

Max Output Tokens

128,000